[oilpan] The Node hierarchy should have correct accept method chains

Source/core/html/shadow/HTMLShadowElement.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 54 matching lines @@
 
     ShadowRoot* older = containingRoot->olderShadowRoot();
     if (!older || older->type() != ShadowRoot::AuthorShadowRoot || ScopeContentDistribution::assignedTo(older) != this)
         return 0;
 
     return older;
 }
 
 void HTMLShadowElement::acceptHeapVisitor(Visitor* visitor) const
 {
-    HTMLElement::acceptHeapVisitor(visitor);
+    InsertionPoint::acceptHeapVisitor(visitor);
 }
 
 } // namespace WebCore